Synthesis of Pyrrolidine-2-ylidenes from Isoxazolines and Allenes.

A diastereoselective addition and rearrangement reaction has been developed for the synthesis of pyrrolidine-2-ylidenes from N-isoxazolines and electron-deficient allenes. This method proceeds via the rearrangement of a proposed -alkenylisoxazoline intermediate to generate densely functionalized pyrrolidine-2-ylidenes under simple catalyst-free conditions that tolerate ketone substituents and install relative stereochemistry at positions 3 and 4 of the heterocycle. Reaction optimization and the substrate scope are described in addition to studies evaluating the reactivity of the -dione and enaminone groups of the products.

Coexistence of Ferromagnetism and Superconductivity at KTaO Heterointerfaces.

The coexistence of superconductivity and ferromagnetism is a long-standing issue in superconductivity due to the antagonistic nature of these two ordered states. Experimentally identifying and characterizing novel heterointerface superconductors that coexist with magnetism presents significant challenges. Here, we report the observation of two-dimensional long-range ferromagnetic order in a KTaO heterointerface superconductor, showing the coexistence of superconductivity and ferromagnetism.

Spontaneous rotational symmetry breaking in KTaO heterointerface superconductors.

Broken symmetries play a fundamental role in superconductivity and influence many of its properties in a profound way. Understanding these symmetry breaking states is essential to elucidate the various exotic quantum behaviors in non-trivial superconductors. Here, we report an experimental observation of spontaneous rotational symmetry breaking of superconductivity at the heterointerface of amorphous (a)-YAlO/KTaO(111) with a superconducting transition temperature of 1.

DNAzyme-driven bipedal DNA walker triggered to hybridize silver nanoparticle probes for electrochemical detection of amyloid-β oligomer.

Amyloid-β oligomer has been considered as a promising molecular biomarker for the diagnosis of Alzheimer's disease due to their significant neural synapse toxicity. Therefore, it is essential to create an easy approach for the selective detection of Amyloid-β oligomer that has high sensitivity and cheap cost. In this work, we developed an innovative enzyme-free electrochemical aptasensor based on the DNAzyme-driven DNA bipedal walker tactics for sensing Amyloid-β oligomer.

DNAzyme-driven bipedal DNA walker for label-free and signal-on electrochemical detection of amyloid-β oligomer.

As a common technique for detecting AβO, the enzyme-linked immunosorbent assay (ELISA) method is time-consuming, high in cost, and poor in stability. Therefore, it is necessary to develop a highly sensitive, method-simple and low-cost method for the selective detection of AβO. Here, we created a novel signal-on and label-free electrochemical aptamer sensor for the detection of AβO based on a DNAzyme-driven DNA bipedal walking strategy.

Two-Dimensional Superconductivity at the Titanium Sesquioxide Heterointerface.

The study of exotic superconductivity in two dimensions has been a central theme in the solid state and materials research communities. Experimentally exploring and identifying exotic, fascinating interface superconductors with a high transition temperature () are challenging. Here, we report an experimental observation of intriguing two-dimensional superconductivity with a of up to 3.

Increased risk of abortion after frozen-thawed embryo transfer in women with polycystic ovary syndrome phenotypes A and D.

Polycystic ovary syndrome (PCOS) is associated with adverse pregnancy outcomes, including an increased risk of abortion, premature delivery, and even neonatal outcomes. After removing the effect of COH on patients, studying the pregnancy outcomes of patients with different PCOS phenotypes after FET may better reflect the impact of different PCOS phenotypes on ART outcomes. Data of 8903 patients who underwent FET between January 2017 and October 2019 were retrospectively collected and evaluated.

The Effects of Anthropomorphism, Message Framing, and Voice Type on Unhealthy Sleep Behavior in Young Users: The Mediating Role of Risk Perception.

Insufficient sleep is a severe social public health problem that can adversely affect the physical and mental health of young people. This study examined risk perceptions for unhealthy sleep behaviors and intentions for healthy sleep behaviors under different combinations of anthropomorphism, message framing, and voice type in cartoons. We used a three-factor between-subject experiment of two (anthropomorphism: anthropomorphic vs.

Nitrone and Alkyne Cascade Reactions for Regio- and Diastereoselective 1-Pyrroline Synthesis.

The synthesis of 1-pyrrolines from N-alkenylnitrones and alkynes has been explored as a retrosynthetic alternative to traditional approaches. These cascade reactions are formal [4+1] cycloadditions that proceed through a proposed dipolar cycloaddition and N-alkenylisoxazoline [3,3']-sigmatropic rearrangement. A variety of cyclic alkynes and terminal alkynes have been shown to undergo the transformation with N-alkenylnitrones under mild conditions to provide the corresponding spirocyclic and densely substituted 1-pyrrolines with high regio- and diastereoselectivity.

A direct solvent-free conversion approach to prepare mixed-metal metal-organic frameworks from doped metal oxides.

We propose a novel strategy to introduce platinum into the metal nodes of ZIF-8 by preloading Pt as a dopant in ZnO (Pt-ZnO) and then convert it to Pt doped ZIF-8 (Pt-ZIF-8) through a chemical vapor deposition (CVD) approach. The solvent-free conversion of Pt-ZnO to Pt-ZIF-8 allows the Pt dopant in ZnO to coordinate with organic linkers directly without the formation of Pt nanoparticles, which is a general issue of many methods. This general synthesis strategy may facilitate the discovery of MMOFs that have not been reported previously.

Decoupling nucleation from crystal-growth for the synthesis of nanocrystalline zeolites.

The increasing demands for catalysts with improved accessibility to reactants call for a rational synthesis of nanosized zeolites. Herein we developed a facile approach for highly crystalline MFI-type (Silicalite-1 and ZSM-5) and beta zeolites with variable Si/Al ratios and high yield. This was achieved by kinetically decoupling the nucleation from the growth process of the zeolites in a highly concentrated gel system via a temperature-staged treatment.

Synthesis of Spirocyclic 1-Pyrrolines from Nitrones and Arynes through a Dearomative [3,3']-Sigmatropic Rearrangement.

A dearomative [3,3']-sigmatropic rearrangement that converts N-alkenylbenzisoxazolines into spirocyclic pyrroline cyclohexadienones has been developed by using the dipolar cycloaddition of an N-alkenylnitrone and an aryne to access these unusual transient rearrangement precursors. This cascade reaction affords spirocyclic pyrrolines that are inaccessible through dipolar cycloadditions of exocyclic cyclohexenones and provides a fundamentally new approach to novel spirocyclic pyrroline and pyrrolidine motifs that are common scaffolds in biologically-active molecules. Diastereoselective functionalization processes have also been explored to demonstrate the divergent synthetic utility of the unsaturated spirocyclic products.

Protective dissolution: generating secondary pores in zeolite by mechanochemical reaction.

Introduction of meso-/macropores into the intrinsic microporous framework of zeolites has raised substantial interest in catalytic reactions with bulky reactants. Herein, we report the formation of secondary meso-/macropores in Silicalite-1 zeolite by a solvent-free mechanochemical grinding process. The strategy allows the preservation of high crystallinity and microporosity of the pristine zeolite, and the generation of mesopores at room temperature and marcopores at higher temperatures.

Clinical efficacy of tirofiban combined with a Solitaire stent in treating acute ischemic stroke.

This study explores the safety and effect of acute cerebral infarction treatment by microcatheter injection of tirofiban combined with a Solitaire AB stent and/or stent implantation. Emergency cerebral angiograms showing the responsible vascular occlusion of 120 acute cerebral infarction patients who underwent emergency endovascular thrombectomy were included in the study. These patients were randomly divided into two groups using the random number table method: treatment group (n=60) that received thrombectomy (with cerebral artery stents) combined with intracerebral injection of tirofiban and control group (n=60) that only received thrombectomy (with cerebral artery stents alone).

Using Machine Learning to Provide Reliable Differentiated Services for IoT in SDN-Like Publish/Subscribe Middleware.

At present, most publish/subscribe middlewares suppose that there are equal Quality of Service (QoS) requirements for all users. However, in many real-world Internet of Things (IoT) service scenarios, different users may have different delay requirements. How to provide reliable differentiated services has become an urgent problem.

Assessment of pre-ejection period in ambulatory subjects using seismocardiogram in a wearable blood pressure monitor.

The ability to monitor arterial blood pressure continuously with unobtrusive body worn sensors may provide a unique and potentially valuable assessment of a patient's cardiovascular health. Pulse wave velocity (PWV) offers an attractive method to continuously monitoring blood pressure. However, PWV technologies based on timing measurements between the ECG and a distal PPG suffer from inaccuracies on mobile patients due to the confounding influence of pre-ejection period (PEP).

Tomato photorespiratory glycolate-oxidase-derived H O production contributes to basal defence against Pseudomonas syringae.

Despite being essential for C plants, photorespiration is believed to cause a significant crop yield loss even under future climates. However, how photorespiration affects plant basal defence still remains largely unknown. Here, we studied the involvement of photorespiration in tomato-Pseudomonas syringae pv.

Genetic diversity and phylogenetic analysis of porcine reproductive and respiratory syndrome virus in southern China from 2007 to 2014.

Porcine reproductive and respiratory syndrome virus (PRRSV) has a high degree of genetic variation. In this study, we characterized the genetic variation and evolutionary relationships among circulating PRRSV strains in southern China. We analyzed 29 NSP2 strains and 150 ORF5 strains from clinical samples collected in southern China during 2007-2014.

Multi-system state shifts and cognitive deficits induced by chronic morphine during abstinence.

Chronic morphine administration induces neural plasticity followed by withdraw. And clinic observation indicates that obvious cognitive deficits are found during withdrawal. However, current neural substrates that regulate dysfunction in withdrawal are unknown.

Sequence analysis of the spike gene of isolated from South China during 2011-2015.

The spike gene of porcine epidemic diarrhea virus (PEDV) was sequenced from 55 South China field strains isolated from pigs with symptoms of diarrhea. The sequences were compared within the set of field strains as well as with reference strains available in GenBank. Within the 55 South China PEDV field strains, the deduced amino acid sequence identities ranged from 93.